I keep getting “FATAL DOWNLOAD_CHUNK Chunk” errors (when running “duplicacy check”) when backing up to wasabi. It’s always the same chunk missing. I’ve deleted the only 1 snapshot several times and re-run backup and again the SAME chunk is missing.

I really wanna like duplicacy, but after quite extensive testing, I am getting the sense that it’s maybe not ready for prime-time yet. Lot’s of spurious errors like these, even if they are not technically duplicacy’s fault, it should be able to recover from them.

2020-07-28 09:18:54.286 INFO SNAPSHOT_CHECK All chunks referenced by snapshot florian_photos-wasabi at revision 1 exist
2020-07-28 09:18:54.607 FATAL DOWNLOAD_CHUNK Chunk d84c4f92025716d61ac... can't be found
Chunk d84c4f92025716d61ac... can't be found

Can you delete the cache under .duplicacy/cache and run the check again? If you manually delete a snapshot file from the storage and then run a backup that reuses the same revision number, the cached copy stored under .duplicacy/cache will still reference the old snapshot and therefore cause missing chunks.

If the problem persists after the cache cleanup then you’ll need to follow the steps described in Fix missing chunks.

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Alright, thanks. That worked. It was the cache. Because had deleted the snapshot before multiple times as instructed in the fix, and that didn’t work.

I do realize that it’s not always possible, but would be nice if there was a way duplicacy could repair the snapshot and force re-upload the missing chunks. Better yet, prevent them happening in the first place. I’ve seen some discussion about making sure that the file is copied and then renamed, etc. Not sure what happened in this case. Let’s hope it was an odd one out.

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Closed this. Not clear why it happened in the first place, but it’s working for now.